Applying for mortgage as sole applicant with joint account

Hi, looking for advice on whether i can apply for a sole mortgage application with the savings from our joint account? We did apply to ICS but my partner has some late payments on a previous loan and they are delving deep into our application and im not sure if we will get approval. So my broker advised that i could apply as a sole applicant with finance ireland using the joint savings account but i got some advice from another broker which seemed to suggest i couldnt use all of the monthly instalments ive paid in but only half that amount. i have proof that i put 3/4 of the savings from my account. Any advice greatly appreciated